Lathe-dog.



PATENTBD APR. 24, 1906.

A. KRUS.

LATHE DOG.

APPLICATION HLBD Arms. 1904.

ANDREW KRUS, OF CHICAGO, lLLlNOlS.

LATHlE-DOG.

Specification of Letters Patent,

Patented April 24, 1906.

Application filed April 6, 1904. Serial No. 201.818.

Be it known that I, ANDREW Knus, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain `new and useful Improvements in Lathe-Dogs, of which the following is a specification.

This invention relates to certain improvements in the construction and arrangement of the parts of a lathe-dog.

The primary objects of my improvements are to provide a device of the character stated which, while adapted to firmly grasp and hold the device inserted therein, may be quickly and readily detached therefrom.

A further object is to so construct such a device that it may be instantly adjusted to the piece held therein and when so adjusted the clamping-j aw proper will be automatically locked on the coacting portions of the device.

Further objects of my improvements are to provide a device thatwill be strong, durable, and in which if any portion should become broken it may be readily and economically repaired.

Having the foregoing and other objects of general utility in view, I have produced the device illustrated in the accompanying drawings and which will be hereinafter fully described.

Referring to the drawings accompanying this application, Figure l is a view, partly in elevation and partly in section, of my invention complete. Fig. 2 is a side view of the same. Fig. 3 is a vie'w on the line 3 8 of Fig. l, and Fig. 4 is a sectional detail, on an enlarged scale, of the special portions of the device on which the main claims for novelty and utility are based.

Referring to the drawings in detail, A represents the fixed head of the clamping-dog, which is made in the usual form and is provided with a central bore to receive and adjust the screw a and is also provided with sockets a2, in which are mounted rack-bars B B, having on their inner faces teeth b. nected with the lower end of the screw c by vsprings c is a clampingeblock C, such connec- Con? Slidably mounted on the rack-bar B is a clamping member D, formed with the usual tail portion d and provided with openings d2, into which are fitted the rack-bars B. ln the center of the member D is an opening through which extends a screw E, to the inner ends of which .is secured a clamping-block F, which blocks are formed with teeth which are adapted to engage the teeth of the rack-bars B when said wedged blocks are moved outwardly in the manner to be described. ln the under side of the blocks G G, which is beveled or inclined correspondingly to the upper side, is inserted a pin' g', which projects from the face of the block and enters a recess d3, formed in the portion d4 of the clamping member D. This recess extends downwardly and outwardly from the center of said portion d4 and has placed therein a coil-spring d5, one end of which rests against the wall at the end of the recess and the other end against the pin g. It 'will be seen that there are two of said recesses, springs, and coacting pins and that same are arranged on opposite sides of the screw E and extend in opposite directions from the latter, all as shown in Fig. 4.

It will be seen from the foregoing that the blocks G, which are, in effect, small dogs, are held between and frictionally engaged by the adjacent walls of the portion d4 of the clamping member and the block and that owing to the inclined faces on said portions thepressure exerted on the block F will tend to push outwardly the blocks G, whereby the teeth of the latter will engage the teeth of the rackbar, and thus lock the parts in position. The tension of the springs d5 is sufficient to retract the blocks G as soon as the pressure is relieved from the block F, and when the blocks are so retracted their teeth will be disengaged from the teeth of the rack-bar, and the member D, together with the block F mounted thereon, may be moved along the rack-bars to any point within the range of the latter, thus permitting a quick adjustment of the member D to its holding-piece When the piece inserted in the clamp has been engaged IOO IIO

by the block F, the grip ofthe dog will be coming-block on said head, rack-bars loosely sepleted by screwing inwardly the screw a.

It will be noted that the rack-bars are pivotally mounted in the head A, thus permitting lateral movement of the same which may be desirable with certain classes of work. It

y, will also be noted that the blocks or little dogs G are the only parts of the adjustable clamping element which are subjected to wear, and as these are made from hardened steel they will be Vextremely durable and when they do wear out it is only necessary to replace them with similar pieces and the device will be practically as good as new. It should also be observed that the connection between the block C and the screw a is such that said block can be readily removed and replaced should it become broken. are other advantages of construction in the device above described which will appear to one skilled in the art and need not be specifically mentioned.

Having thus described my invention7 what I wish to claim, and secure by Letters Patent, is-

l. In a lathe-dog, a iixed head, a clampingblock adjustable on said head, rack-bars secured to said head, an adjustable clampingheadarranged on said rack-bars and formed with inclined slideways therein, blocks mounted in said slideways and having teeth on their outer 'faces adapted to engage said rack-bars, springs arranged in said clampinghead and adapted to retract said toothed blocks, a clamping-block having a beveled face bearing on said toothed blocks and means for adjusting said clamping-block.

2, In a lathe-dog, a fixed head, a clamp- There cured to said head and having teeth on their inner sides, a clamping head slidably arranged on said rack-bars and having inclined slideways therein, blocks slidably mounted in said slideways and having teeth adapted to engage the rack-bar teeth, means for automatically disengaging said 'blocks from said rack-bars, a clamping-block adjustably mounted on said slidable clamping-head and having portions bearing on said toothed blocks and adapted to force said blocks outwardly, means for adjusting said clampingblock and for locking it in its adjusted position.

3. In a lathe-dog provided with a suitable head, a clamping-block adjustable on said head, rack-bars secured to said head, an adjustable clamping-head slidably mounted on said rack-bars, blocks mounted on said member and having teeth adapted to engage said rack-bars, said blocks adapted to be automatically and simultaneously thrown into engagement with said rack-bars upon pressure being applied to the clamping-head, springs secured to said clamping-head and adapted to automatically and simultaneously disengage said blocks from said rack-bars upon pressure being relieved from said clampinghead and means for locking said blocks in engagement with said rack-bars.

In testimony whereof I affix my signature in presence of two witnesses.

ANDREW KRUS.

Witnesses:

A. A. BooK, F. BENJAMIN. 

